1 You need to be on ofw 3.55 if you are lower u need to upgrade and if higher you need to downgrade
2 now from that ofw you can install a cfw 4.21 for ex witch allows you to install backup games managers (like multiman)

For both downgrade and then cfw you find tutorials on this site

Azrial - so there is no way to downgrade a superslim ps3 without a dongle, just with a .PUP?